The table lamp is a moveable lighting tool, which can be disposed on a desk or a table for illumination. The illumination range of a table lamp is very small, and hence light of the entire room will not be influenced when a table lamp is used for illumination. Moreover, since a table lamp usually has very concentrated light, it can be widely used for the illumination of reading, studying and so on. In order to achieve an optimal illumination angle for a table lamp, it is usually necessary to adjust the illumination angle of the table lamp.
In the prior art, there is a table lamp with an adjustable illumination angle, which can also be called an omnidirectional lamp. The omnidirectional lamp usually comprises: a base, a lamp handle and a lamp holder provided with a light source, wherein the lamp handle is in fixed connection with the base and the lamp handle is in moveable connection with the lamp holder. To ensure that the omnidirectional lamp can be placed steadily, a contact surface where the base contacts a placement surface of the omnidirectional lamp is usually planar. In the adjustment of the illumination angle of the omnidirectional lamp, the Omnidirectional lamp is placed on the placement surface via the base, and the lamp holder of the omnidirectional lamp is rotated up and down such that the illumination angle of the omnidirectional lamp achieves the optimal illumination angle.